Apparatus and method for controlling the liquid level in a washing machine



1 3,086,836 5 AND METHOD FOR CONTROLLING THE E N I H C m m NI Nw m H mwm v E L m ww I ML P P. A 3 6 9 1 "m p A 2 Sheets-Sheet 1 Filed Oct. 17,1960 fni/E'nfar' William. Oiimann LZL/z Eff 5.

A ril 23, 1963 w. OHMANN 3,086,836

APPARATUS AND METHOD FOR CONTROLLING THE LIQUID LEVEL IN A WASHINGMACHINE 2 Sheets-Sheet 2 Filed Oct. 17, 1960 POWER 120 SOURCE [Hz E110!" ii/dam Oifimann 441 f[ /5 United States Patent 3,085,835 APPARATUSAND METHOD FUR CGNTROLLWG THE LIQUED LEVEL IN A WASI WG William Ohmann,Benton Harbor, Mich, assignor to Whirlpool Corporation, St. Joseph,Mic-11., a corporation of Delaware Filed Oct. 17, 1969, Ser. No. 62,95515 Ciaims. (Ci. 8-158) This invention relates to a washing machinehaving a water level control, and more particularly to a washing machinewherein the correct amount of fluid is selected for the requirements ofa given load of clothes, automatically and with no pro-selection by anoperator.

Although there has been a long standing need for automatic water levelcontrol in a washing machine, both from the standpoint of saving waterand for the purpose of providing an effective Washing action, allefiorts to provide same have heretofore been unsuccessful. The presentinvention provides a solution to this problem which includes means forintroducing an amount of water into the tub which is determined inaccordance with the actual requirements of a specific load of clothes,without any need for estimating or pre-selection on the part of theoperator.

It has been determined that any given load of clothes will absorb waterin proportion to its mass, i.e., its absorbency, weight and volume.Consequently, if a given amount of water is introduced into a washingmachine, the amount not absorbed or retained by the clothing in themachine is inversely proportional to the mass of the clothing. Thisinvention employs such proportionate relationship to produce a signalfor presetting a water level switch whereby the machine may be filledonly to the level necessary for a given load, so as to afford desiredeconomies in operation.

Accordingly, spray means are utilized to introduce a predeterminedamount of water into a spinning load of clothes, and a water pick-uparea is built into the tub at either the bottom or outside of the tub.There are several methods of metering this predetermined amount of waterinto the load, but they do not form a part of this invention. In apreferred form of the invention, a collector rib is formed in the tuband a pressure-sensitive device is attached to the water pick-up area incommunication with the collector rib, whereby to preset the contacts ofthe water level switch.

' The invention contemplates the use of a manometer as thepressure-sensitive device, with valve means for introducing watercollected by the spraying operation into an air trap of the manometer,the valve being shut ott after the spraying operation so that as the tubis filled, preferably through a separate fill conduit, water will becollected above the shut off valve with the result that as the waterlevel rises in the tub it will increase the air pressure in themanometer which will actuate a pressuresensitive switch at apredetermined level of pressure to terminate filling of the tub at alevel inversely related to the amount of sample spray fluid collected inthe air trap during the preliminary spin operation of the dry load whenthe load size sampling fluid is introduced to the load.

It is, therefore, an object of the present invention to provide a methodfor determining the water level required for effective washing of aspecific load of clothes or the like, and for transposing thatdetermination for controlling means to produce that level.

Another object of the invention is to provide a device as describedwhich reduces vibration and wear in the machine by assuring that theload is immersed in a sufficient amount of water.

Another object of the invention is to provide a device 3,936,836Patented Apr. 23, 1963 "ice as described wherein water and detergentsavings are effected by the elimination of over-filling of the tubrelative to the requirements of a specific mass of clothes.

Another object of the invention is to provide a device as describedwhich is entirely self-operating and automatic.

Another object of the invention is to provide a washing machine whichcontrols the amount of water introduced into the tub precisely inaccordance with the requirements for a specific wash load.

Other objects and advantages of the invention will become apparent asthe description proceeds in accordance with the drawings in which:

On the drawings- FIGURE 1 is a vertical sectional view, partly brokenaway, of a washing machine according to the present invention;

FIGURE 2 is a top plan view of the structure shown in FIGURE 1; and

FIGURE 3 is a schematic showing of a circuit for use in the washingmachine of the invention.

As shown on the drawings:

As seen in FIGURE 1, a washing machine 10 according to the inventionincludes a tub 12 in which is mounted a foraminous basket 14 supportedfor rotation on a drive shaft 16 which is adapted to be driven throughgear means 18 energized by a motor 29 as shown schematically in FIGURE3. An agitator 22 is mounted on the shaft structure 16 to be drivenselectively in accordance with a presettable sequential control asunderstood by those skilled in the art.

In accordance with the invention, and as hereinafter further described,a predetermined amount of water is introduced into the basket 14 by aspray conduit 24 during a sample fill period so that a load to be washedwhich has been placed in the machine it} Will absorb the fluidproportionately to its mass, volume and absorbency, so that a proportionof the unabsorbed metered fluid thus introduced may be used as a signalto control a pressuresensitive device 26.

In order to eifect such control, a water pickup area is provided towhich water is directed by a collector rib 28 which may be secured tothe internal surfaceof the tub 12 by screw means or the like 39 engaginga flange 32 of rib 23 and tub 12, and having a downwardly inclined,inwardly extending rib portion 34 formed integrally with the flange 32.The rib portion 34- is configured to channel water collected duringspinning of the basket 14 as the water is sprayed during a predeterminedinterval from the conduit 24, the water thus collected beingproportionate to the remainder of fluid not absorbed by the load in thebasket during the spray interval. It should be understood that collectorribs of different length and shape could also be used.

In a preferred form of the invention, the pressuresensitive device 26comprises a manometer including a base portion having a tall leg 36 anda short leg 38, so that the base housing 40 forming the tall and shortlegs 36 and 38 provides an air trap in short leg 33 as hereinafterfurther described. The relative heights of legs 36 and 38 may vary sincethe entire manometer assembly further includes tubular extensions 56 and68 to be further described.

Fluid collected by the rib 34 is thus introduced into thepressure-sensitive device 26 through a Water pickup connection or inlet42 positioned in tub 12 at the base of the collector rib- 28, and havinga downwardly turned portion 44- connected to the tall leg 36 by aflexible conduit 46. Suitable sealing rings or the like 48 and 50 areutilized to connect the upper end of the hose 46 to the portion 44 andthe lower end of the hose to a lip 52 on the tall leg 36. The hose iscontrolled by a shut off valve 54 or the like also as hereinafterfurther described.

In order to transmit further pressure to pressure switch 66 during thewash and deep rinse fill periods to enable pressure switch 66 to betripped to end the fill periods, a tube 56 of inverted U-shapedconfiguration is connected to an adaptor structure 53 on the portion 44-by a clamp ring 69 or the like, and communicates with the upper endof'the leg 36 by means of an adaptor structure 62 thereon and is sealedby a clamping ring 64 or the like.

A presettable pressure responsive switch 66 is mounted at the upper endof a reduced tube 68 which is connected to the short leg 3'8 by anadaptor structure 76 and a clamping ring 72. Signal water is removedfrom the manometer between successive loads by means of a valve 74normally closing a flexible conduit 76 connected to an outlet '78 in thehousing 40 by a sealing or clamping ring 89 or the like, the other endof the conduit '76 being connected to a small filter pump 82 in pumphousing 81 through a conduit structure 84 to which the hose 76 issecured by a ring or the like 86. A second filter pump inlet conduit 88is connected to the other side of the conduit structure 84, as by a ring90 or the like, it being appreciated that the filter conduit 88 isconnected to the side of the tub 12 (not shown). An outlet from thefilter pump 82 (not shown) is provided to deliver fluid from conduits 76and 88 through a filter (not shown) and back into tub 12. A conduit 92is provided in the bottom of tub 12 to drain tub 12. Conduit 92 leads tothe main pump portion 83 of pump housing 81. A conduit 94 leads to drainfrom main pump portion 83. Main pump 83 pumps either from conduit 92 toconduit 94 or :Erom conduit 94 to conduit 92.

Accordingly, a simple and effective metering of a desired amount ofwater into the tub for washing a specific load without vibration andwithout waste of water may be accomplished by means of thepressure-sensitive means 26. Thus the operator places the dry clothes inthe basket 14 and by pre-selection on a presettable sequential controlmeans (not shown) selects the wash cycle preferred for the type ofclothes to be washed whereby the machine will be automatically operatedthrough a programmed schedule of washing, rinsing and extractingperiods. When the lid of the machine (not shown) is closed, the machineis started and spins the dry clothes for a predetermined sample fillperiod, which may, for example, be one minute. During this spin cycle,cold water is sprayed into the basket 14 and tub through the sprayconduit 24, as determined by switch means hereinafter described. Byusing an orifice of known size and a selected time interval, the flowrate may be predetermined so that, for example, 1% gallons of Water orsome other predetermined amount of fluid is sprayed on the clothes load.Other means could also be used to assure 1% gallons. As indicated, theclothes absorb or retain part of this spray while the rest of the sprayimpinges upon the tub wall due to the centrifugal force generated by thespinning basket 14. A portion of this unabsorbed spray is collected bythe collector rib 28, and is guided into the air trap housing 40 throughthe inlet 42, by automatic opening of the valve 54. The water thusintroduced into the housing 40, if enough is collected in housing 40,rises above the level shown at 41 causing air to be trapped in the shortleg 38 to exert pressure on the pressure switch 66 and thereby conditionor preset the switch 66. The degree or extent of pressure build up inthe tube 68 at the end of the spin and spray period completelydetermines the quantity of water that will enter tub 12 during the washand deep rinse fill periods before pressure switch 66 is tripped.

Since collector rib 28 collects only a portion of the fluid which is notabsorbed or retained by the fabrics, it will be appreciated that thesensing control apparatus regulated by such reduced portion may be ofsomewhat smaller proportionate size for accomplishing the objectives ofthis invention.

At the end of the predetermined spray and spin interval, the valve 54closes and water is introduced into the machine through a conduit 96,the conduits 24 and 96 being connected to a mixer valve 93. Althoughboth conduits 24 and 96 are used in the explanation of this iI1V6I1--tion, it should be appreciated that to carry out the principles of thisinvention it would be sufficient to have a system in which mixing valve98 would control the sample metered amount of water as well as thewashing and rinsing water and have only a single conduit leading fromthe mixing valve to the machine. When the Water level in tub 12 reachesthe level shown at 43 in FIGURE 1, the air in inverted tube 56 isentrapped and the air pressure above the sample Water in tube 36 willincrease as the water level in tub 12 increases. This increased airpressure in tube 56 causes the height of the sample water in tube 68 tobe increased causing the air in tube 68 to be further compressed. Thisincreased pressure in tube 63 soon reaches the predetermined value ofpressure switch 66 thus causing pressure switch 66 to deenergize mixervalve 98 to stop the flow of inlet Water through conduit 96.

The machine then passes through its wash cycle, including draining bymeans of the main pump 83 upon completion of the washing operation,filling and rinsing, subsequent draining, and spinning, as understood bythose skilled in the art. The deep rinse cycle will automatically fillto the level determined for the wash cycle as a result of the presettingof the switch 66.

It will be understood that after the manometer has been set for aparticular wash load, the signal water must be drained out before thenext load of clothes is put into the machine. This is accomplished byopening the valve 74 at the bottom of the manometer, and this may bedone at any time after the deep rinse.

Referring now to FIGURE 3, the circuit for the machine 10 is illustratedschematically as including a power source 100, a push-pull switch 106and the various electrical devices are controlled by a sequentialcontrol means. The control means has a timer motor 121 which rotatablydrives a plurality of cams associated with a corresponding plurality ofcam operated switches. The circuitry also includes the pressure or waterlevel switch 66, which has a switch element 112 connecting with acontact 114 when the tub is empty as at the beginning of an operation,and engaging a contact 116 when water has been introduced into the tubto the correct level.

The push-pull switch 106 is actuated by the operator and the cam C-1controls a line switch 102. A cam C-2 controls a switch 117 forenergizing the motor 120 of the manometer fill valve 54 and the spinsolenoid 118 for operating the basket at centrifuging speed.

The cam C-3 regulates energization of the timer motor 121 through switch124 while the cam C-4 regulates the actuator 134 of the manometer drainvalve 74 through the upper contact 136 and the agitator solenoid 132through the lower contact 130.

The cam C-5 regulates the main drive motor 20 through the switch 108.The cam C-6 regulates the twoway water fill mixer valve 98 to charge themachine with liquid via the inlet 96 when the bottom contact 126 isclosed to energize the solenoid 128 and to discharge a metered amount ofliquid via the nozzle 24 when the top contact 122 is closed to energizethe solenoid 123.

In operation, the spin solenoid 118, manometer fill valve solenoid 120,and spray solenoid 123 in addition to drive motor 20 are initiallyenergized for a specific time interval so a metered flow of liquid willbe introduced into the machine through conduit 24 to condition theswitch 66. Thereafter the valve 54 is closed and the contact 126 thenenergizes the Water fill solenoid 128 to introduce fluid through theconduit 96, the Water level switch 66 still being at the empty positionwith element 112 contacting contact 114. At this time, cam C-2 hasopened switch 117. After the predetermined amount of pressure has beenobtained in the switch 66, element 112 will move to contact 116, tode-energize the solenoid 128 and terminate the flow of fluid into thetub. The agitator 22 will be energized through a switch 130 and anagitator solenoid 132, or the like, it being understood that the mainpump means 83 for the machine is mechanically operated to pump fromconduit 94 to 92 whenever the agitator solenoid 132 is energized thusacting to hold the water in the tub 12.

The timer motor 121 will control the sequential progress of the fill andWash and fill and rinse cycles, the drain cycles and spin cycles, andduring the final spin cycle, the manometer drain solenoid 134 will beenergized through the upper contact 136 to allow the manometer to drainto the filter pump 32 from Where the Water is pumped through the filter(not shown) into tub 12 to be pumped to drain. Of course, the manometerfill valve 54- is open whenever the basket 14 is spinning.

The device may be calibrated so that a predetermined minimum water levelwill always be achieved, e.g., a level of seven inches, and so that amaximum level, e.g., eleven inches, is determined, thereby assuringeffective washing conditions for substantially all loads. As a result ofthe water level control system described, however, appropriate waterlevels for loads of intermediate mass, volume and absorbency will beafiorded with a high degree of accuracy.

Accordingly, there has been provided a washing machine of fullyautomated character wherein the amount of water is determinedpragmatically in accordance with the requirements of the wash load. As aresult, the machine will be filled sufficiently so that agitation of theclothes will not produce undue vibration and wear on the machine, whichoccurs when an insufiicient amount of water is present, and also, theamount of fluid is limited to the spechic requirements of the particularload so that there is no waste. This water level system also assuresthat there will always be enough Water present to effect a quality washwithout using superfluous amounts of water and detergent.

Although I have herein set forth and described my invention with respectto certain specific principles and details thereof, it will beunderstood by those skilled in the art that these may be varied withoutdeparting from the spirit and scope of the invention as set forth in thehereunto appended claims.

I claim as my invention:

1. In a machine for liquid treatment of materials hav ing a containerreceiving the materials, liquid control ap-/ paratus comprising meansfor determining the relative amounts of liquid absorbed and not absorbedby a specific mass of absorbent material disposed in said container, andmeans controlled by said means for determining from said relativeamounts the amount of liquid required in said container and forintroducing such required amount of liquid into said container.

2. In a machine for liquid treatment of materials having a container,liquid control apparatus comprising, liquid supply means for introducinga predetermined quantity of liquid into said container, means fordetermining the amount of such liquid not absorbed by a mass of materialin said container, and means for introducing an amount of liquid intosaid container proportionate to the determination of the amount notabsorbed.

3. In a machine for liquid treatment of materials having a container,liquid control apparatus comprising, means for determining the amount ofliquid absorbed by a specific mass of absorbent material therein, meansfor introducing liquid into said container upon obtaining saiddetermination, and means for terminating said introduction of liquidinto said container in accordance with the determination provided bysaid determining means.

4. In a machine for liquid treatment of materials having a container, aliquid control apparatus comprising, means for introducing apredetermined quantity of liquid into the container, means forcollecting an amount of liquid proportionate to the introduced liquidnot absorbed by a mass of material in said container, means forintroducing further liquid into said container, and control meansterminating said introduction of said further liquid in accordance withthe amount of collected liquid.

5. In a washing machine having pre-settable sequential control means, atub and a foraminous basket in the tub, means for spinning the basket,means for introducing a predetermined quantity of liquid into said tub,means for collecting an amount of said liquid proportionate to theamount of liquid absorbed by a mass of material in the basket when thebasket is spun, and means for introducing further liquid into said tubin proportion to the amount of liquid collected by said collectionmeans.

6. In a washing machine having presettable sequential control means, atub and a foraminous basket in the tub, means for spinning the basket,means for introducing a predetermined quantity of liquid into said tub,means for collecting an amount of said liquid proportionate to theamount of liquid absorbed by a mass of material in the basket when thebasket is spun, means for introducing fur-ther liquid into said tub, andmeans for terminating said introduction of further liquid into said tubin accordance with the amount of liquid collected by said collectionmeans.

7. In a washing machine having a tub, a water level control comprising amanometer, means for introducing an amount of water into said manometerproportionate to the absorbency of fabrics placed within said tub, andcontrol means for introducing a further amount of liquid into said tubproportionate to the amount introduced into said manometer.

8. A washing machine having a presettable sequential control, a tub, aforaminous basket for receiving absorbent articles to be washed, meansfor spinning the basket for a predetermined interval, means forintroducing a predetermined quantity of liquid into the tub during saidpredetermined interval, a collector rib on the tub for receiving anamount of liquid from the basket according to the amount of thepredetermined liquid absorbed by said articles, a manometer connected tosaid tub, an entry valve controlling liquid flow from said rib to saidmanometer, switch means operable in accordance with pressure in saidmanometer, and means for introducing a further supply of liquid into thetub as determined by said switch means and proportionate to the amountof liquid absorbed by said articles.

9. A washing machine having a pre-settable sequential control, a tub, aforaminous basket for receiving articles to be washed, means forspinning the basket for a pre determined interval, means for introducinga predetermined quantity of liquid into the tub during saidpredetermined interval, a collector rib on the tub for receiving aproportionate amount of liquid from the basket according to the amountof the predetermined liquid absorbed by said articles, a manometerconnected to said tub, an entry valve controlling liquid flow from saidrib to said manometer, switch means operable in accordance with pressurein the manometer, means for introducing a further supply of liquid intosaid tub as determined by said switch means and proportionate to theamount of liquid absorbed by said articles, and drain means forsequentially clearing liquid flowing from said manometer.

10. A washing machine having a pre-settable sequential control, a tub, aforaminous basket for receiving articles to be washed, means forspinning the basket for a predetermined interval, means for introducinga predetermined quantity of liquid into the tub during saidpredetermined interval, a collector rib on the tub for receiving aproportionate amount of liquid from the basket according to the amountof the predetermined liquid absorbed by said articles, a manometerconnected to said tub, an entry valve controlling liquid flow from saidrib to said manometer, switch means operable in accordance with pressurein said manometer, and means for introducing a further supply of liquidinto the tub as determined by said switch means and proportionate to theamount of liquid absorbed by said articles, said manometer including airtrap means affording pressure in said manometer proportioned additivelyto the liquid in the manometer and to the liquid in said tub.

11. In a washing machine having container means for receiving liquid andmaterials to be Washed therein, liquid control means comprising, conduitmeans for supplying liquid to said container including means to wet saidfabrics, and means for determining the amount of liquid not absorbed bysaid fabrics and regulating operation of said conduit means forcontrolling the amount of liquid supplied to said container means inresponse to said determination.

12. In a Washing machine having container means for receiving fluid andmaterials to be Washed therein, liquid control means comprising, conduitmeans for supplying liquid to said container means during a sample fillcycle and during a regular fill cycle and including sequential controlmeans regulating the flow of liquid through said conduit means duringsaid cycles, and means influenced by the amount of liquid not absorbedby said fabrics during said sample fill cycle and cooperating with saidsequential control means for regulating the amount of liquid supplied tosaid container means during said regular fill cycle.

13. A method of controlling the amount of liquid in a liquid treatmentmachine comprising, placing a specific mass of material to be treated ina container in the machine, filling the container with a predeterminedamount of liquid, collecting an amount of the liquid proportionate 8 tothe amount thereof absorbed by the mass of material, introducing furtherliquid into the container and using the collected liquid and a portionof the further liquid to energize control means to terminateintroduction of liquid to said container.

14. The method of controlling the amount of liquid supplied to a washingmachine for Washing fabrics during a washing process comprising, wettingsaid ifabrics during a sample fill period, separating from said fabricsthe liquid not absorbed by said fabrics during said sample fill period,and subsequently supplying liquid to said machine for said washingprocess in an amount corresponding to the amount of liquid not absorbedby said fabrics.

15. The method of controlling the amount of liquid supplied to a washingmachine for Washing fabrics during a Washing process comprising,centrifuging said fabrics, wetting said fabrics with a predeterminedquantity of liquid, collecting liquid not retained by said fabricsduring the centrifuging thereof, adding additional liquid to saidmachine, and correlating the amount of liquid subsequently supplied tosaid Washing machine with the amount of liquid collected to control theamount of liquid ultimately supplied to said washing machine for saidwashing process.

References Cited in the file of this patent UNITED STATES PATENTS2,210,851 Davis Aug. 6, 1940 2,554,672 Johnston May 29, 1951 2,934,928Shelton May 3, 1960

13. A METHOD OF CONTROLLING THE AMOUNT OF LIQUID IN A LIQUID TREATMENTMACHINE COMPRISING, PLACING A SPECIFIC MASS OF MATERIAL TO BE TREATED INA CONTAINER IN THE MACHINE, FILLING THE CONTAINER WITH A PREDETERMINEDAMOUNT